What should an organization do if they want to configure email delivery for some users to be in Gmail while others go to a legacy mail system?

To achieve a setup where some users receive their email in Gmail and others continue to use a legacy mail system, the most effective approach is to add users to an organizational unit (OU) specifically for those on the legacy mail system and then configure routing settings for that OU. This allows for flexible management of email delivery based on the organizational structure.

By creating an organizational unit for users who require legacy mail services, administrators can apply specific routing rules that direct their email to the legacy system while leaving other users to operate within Gmail. Google Workspace allows configuration of routing settings at the OU level, which enables granular control over where emails are delivered based on the particular needs of different user groups.

Utilizing a shared mailbox for dual delivery, setting up email aliases, or routing all email traffic to the legacy system do not provide the same level of functionality and control. A shared mailbox implies that emails would be sent to one location rather than separating users’ environments. Email aliases are primarily for sending and receiving mail under multiple names, which does not address the core issue of directing emails to different systems based on user classification. Routing all traffic to the legacy system would result in a complete lack of use of Gmail for the specified users, undermining the purpose of having a mixed system